High-Resolution NMR Spectroscopy in Inhomogeneous Fields Via Intermolecular Multiple-Quantum Coherences Between Spin 1/2 and Quadrupolar Nuclei

Zhong Chen¹, Shuhui Cai¹, Song Chen¹

A heteronuclear CRAZED pulse sequence was designed to detect high-resolution NMR spectra in inhomogeneous fields via intermolecular zero-quantum coherences (iZQCs) or intermolecular double-quantum coherences (iDQCs) between spin 1/2 and quadrupolar nuclei. It overcomes the difficulty of selective excitation in homonuclear CRAZED experiments when the chemical shifts of solvent and solute are close to each other. In the 1D spectrum extracted from the 2D data, chemical shifts, coupling constants, multiplet patterns, and relative peak areas are almost independent of the magnetic field inhomogeneity.